Importance of 99Tcm-MIBI SPECT/CT fusion imaging in primary and secondary hyperparathyroidism

Abstract

Objective The value of 99Tcm-MIBI SPECT/CT fusion imaging in primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT) was evaluated. Methods A total of 97 HPT patients (28 PHPT patients and 69 SHPT) were enrolled in this retrospective study. The 99Tcm-MIBI SPECT/CT imaging features, clinical symptoms, serum PTH, Ca, P, and AKP were analyzed. The following data were compared between PHPT and SHPT patients: imaging features; pathological findings; laboratory examination results; and relevance of diagnostic efficiency and clinical index. Results (1) The sensitivity and specificity of 99Tcm-MIBI SPECT/CT in PHPT were 96.55% and 98.78%, respectively. By contrast, the sensitivity and specificity of 99Tcm-MIBI SPECT/CT SHPT were 68.77% and 79.17%, respectively. (2) PHPT generally exhibited single lesion with average diameter was 17.4 mm. Compared with PHPT, SHPT generally displayed more lesions with smaller diameter of 12.8 mm (Z=-2.591, P=0.010) and more likely to be found with calcification(χ2=9.588, P<0.01). (3) The percentage of patients without special clinical symptoms was higher in PHPT(χ2=11.713, P<0.001). The percentage of patients with calculus in urinary system was also higher in PHPT(χ2=6.075, P<0.001). However, the percentage of patients with ostalgia was higher in SHPT(χ2=24.382, P<0.001). Serum PTH and AKP were significantly higher in SHPT(Z=-6.663,-4.326, both P<0.001). PHPT had high serum calcium level and low phosphorus level, whereas SHPT showed normal or slightly higher calcium level and significantly high phosphorus level. Conclusions 99Tcm-MIBI SPECT/CT fusion imaging had a significant value in preoperation localization of HPT, especially in PHPT. Compared with PHPT, SHPT had a greater increase in serum PTH and AKP and usually exhibited several lesions which are smaller and more likely to accompany calcification. Key words: Technetium Tc 99m sestamibi; Single-photon, emission-computed, Tomography; Hyperparathyroidism, primary; Hyperparathyroidism, secondary